Electric motor



July 7, 1925.

H. R. STUART ELECTRIC MOTOR Filed June 26, 1924 annua Patented July 7,192 5.

UNITED STATES 1,545,213 PATENT OFFICE.

HARVE R. STUART, OF SPRINGFIELD,'OHIO, ASSIGNOR TO THE ROBBINS & MYERSCOMPANY, OF SPRINGFIELD, OHIO, A CORPORATION OF OHIO.

' ELECTRIC MOTOR.

To all 'w/zmnit may concern:

Be it known that I, HARVE R. STUART, a

citizen of the United States, residing at Springfield, in the county ofClark and State of Ohio, have invented certain new and usefulImprovements in Electric Motors, of which the following is ,aspecification.

This invention relates to electric motors, particularly to motors of therepulsion induction alternating current type, and the inventionespecially relates to the feature of changing the direction of rotationof the motor by providing improved means for shifting the brush from oneside of the neutral point to the other.

The object of the invention is to provide a novel form of brush holderwhich may be readily shifted from one side of the neutral point to theother side of the neutral point,

a more specific object of the invention being to provide a brush holderso constructed and arranged that the brush may be quickly and readilyreversed by rotating the holder in its support.

In the accompanying drawings:

Fig. 1 is an end View of a motor showing the brush holders embodying theimprovements, the motor casing being partly broken away and shown insection.

Fig. 2 is a'side elevation of one end of the motor and its casingshowing one of the brush holders.

Fig. 3 is a vertical section of one of the brush holders and its brush.

Fig. 4 is a section on the line 4-4 of Fig. 3.

Fig. 5 is an end view of the holder.

teferring to the drawings, 1 represents the casing of the motor, 2 thearmature shaft, and 3 the commutator. Each of the brush holders consistsof a main cylindrical shell 4 having an integral hollow extension 5which projects from the shell at an angle. An opening 6 extendingentirely through the shell and extension is formed during the process ofcasting, the upper portion of this opening in the shell being enlargedand threaded as indicated at 7 while the walls of the remainder of theopening are milled to form two diametrically-opposite straight sidedgrooves 8 to receive the brush 9. The opening in the shell 4 is closedby a threaded plug 10 and interposed between the plug and brush is acoil spring 11 to apply pressure to the brush.

The cylindrical shell 4 of each of the holders is mounted in the'casing1 of the motor, the casing being provided with an opening 12 for eachholder within which the shell portion is rotatably mounted, the holderbeing held in different positions of adjustment by a set-screw 13 whichis threaded in a boss 14 formed integrally with the casing and adaptedto engage in either one of two diametrically-opposite recesses 15 formedin the walls of the shell 4. Each of the holders is so disposed in thecasing that its axis of rotation is perpendicular to the axis ofrotation of the armature shaft while the brush channel of the holderprojects at an angle to said perpendicular line, which line alsorepresents the neutral point.

iVhen it is desired to reverse the direction of rotation of the motor,the set screws are loosened and each of the brush holders revolved 180degrees, which by reason of the angular relation which the brush channelbears to the axis of rotation of the body portion 4, will locate thebrush on the opposite side of the neutral point indicated by the line16. After the brush holders have been relocated the set-screws aretightened to hold the holder in their new position.

Vhile I have shown the brush channels of the holders projecting at anangle to the axis of rotation of the holder in the motor casing, I donot desire to be limited to this particular arrangement as equally goodresults may be obtained by otherwise offsetting the channel with respectto the axis of rotation so that in one position of the holder the brushwill lie on one side of the neutral point and in the other position ofthe holder the brush will lie on the other side of the neutral point.

Having thus described my invention, I claim:

1. In an electric motor, a support for a brush holder, a holder and itsbrush rotatably mounted in said support with the brush supported in aposition at one side of the axis of rotation of said holder, for thepurpose specified.

2. In an electric motor, the combination, with a commutator, of asupport for a brush holder, a brush holder rotatably mounted in saidsupport with its axis of rotation on the neutral line, and a brushsupported by said holder in a position at one side of the axis ofrotation thereof so that rotation of'said holder will place said brushon one'side or the other ofthe neutral hne. V V I i I 3. In an electricmotor, a support, for a brush, a holder consisting of a cylindrical witha commutator and support, of a brush holder rotatably mounted in; saidsupport with the: axis of rotation thereofi coincident Withthe linerepresentingjthe neutral point, said: holder having an angularlyprojecting channelled extension, and a brush mounted in said channelledextension whereby rotation of the holder Will place the brush on oneside or the other of the neutral line.

5; In an electric motor, the-combination,

with a commutator and siipport, of a brush holder consisting of a.cylindrical shell and provided With a channel, a brush mounted insaidchannel, a plug threaded in said and brush, said extension beingprojected the neutral point whereby said-brnshmay 'beplaeed oneither-one side or the other of.

said neutral point by rotation of said sliell. In testimony whereof 'I'have hereunto set my hand this 16th day of June, 1924.

HARVEY R. STUART she'll, a: spring interposed between said plug 7 V atan angle from said shell and theaxi s of rotation of said shell beingcoincident with

